docs: def gen_html(row_list):
          """ Return html table string from a list of data rows """
          table = "<table>"
          for row in row_list:
              table += "<tr>"
              cells = row["cells"]
              for c in cells:
                  t = c['cell'] if c else ''
                  table += t
              table += "</tr>"
          table += "</table>"
          return table